Electric-powered self-balancing unicycle

ABSTRACT

An electric powered self-balancing unicycle may include a single wheel assembly having a drive system substantially contained within the wheel, a frame and handlebars including a four-bar linkage mechanism pivotably connected to the wheel assembly by a fork.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/973,925, filed Aug. 22, 2013, which claims priority to U.S.Provisional Patent Application Ser. No. 61/692,131, filed Aug. 22, 2012,U.S. Provisional Patent Application Ser. No. 61/709,924, filed Oct. 4,2012, U.S. Provisional Patent Application Ser. No. 61/817,817, filedApr. 30, 2013; and U.S. Provisional Patent Application Ser. No.61/863,064, filed Aug. 7, 2013, each of which is hereby incorporatedherein by reference in its entirety for all purposes.

INTRODUCTION

The need for new forms of transportation is ongoing in modern societiesworldwide. One challenge in designing vehicles for transportationinvolves balancing energy efficiency, good usability, and userenjoyment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an embodiment of a powered unicycle showingthe relationship between certain major components.

FIG. 2 is an isometric view of an embodiment of an electric-poweredself-balancing unicycle.

FIG. 3 is a side elevation view of the powered unicycle of FIG. 1.

FIG. 4 is an isometric view of an embodiment of a wheel suitable for useon a powered unicycle.

FIG. 5 is a sectional view of the wheel of FIG. 4 taken at line 5-5.

FIG. 6 is an isometric view of an embodiment of a seat portion suitablefor use on a powered unicycle.

FIG. 7 is a side elevation view of a frame portion of the poweredunicycle of FIG. 2.

FIG. 8 is a top isometric view of the frame portion of FIG. 7, showingan implementation of the mechanism of FIG. 9.

FIG. 9 is a schematic diagram of an illustrative four-bar linkagemechanism.

FIG. 10 is an isometric view of an embodiment of an electric-powereddrive system.

FIG. 11 is an isometric view of the drive system of FIG. 10, viewed froman opposite side.

FIG. 12 is an isometric view of selected drive components of the drivesystem of FIG. 10.

FIG. 13 is a rear plan view of a portion of the powered unicycle of FIG.2, showing connections between a fork, drive housing, hub plates, andfoot pegs.

FIG. 14 is a side elevation view of another embodiment of a drive systeminstalled in a hubless wheel.

FIG. 15 is a side view of a portion of the drive system of FIG. 14,showing the interaction between a drive sprocket and a ring gear.

FIG. 16 is an end sectional view of another embodiment of a hublessdrive system.

FIG. 17 is an isometric view of an embodiment of a powered unicyclehaving a gurney affixed thereto.

DETAILED DESCRIPTION

An electric-powered self-balancing unicycle is described and illustratedin the present disclosure. Generally, an electric-powered self-balancingunicycle may include a single wheel assembly connected to a frame, theframe supporting a seat and handlebar for a human rider. In someexamples, a unicycle may be self-balancing with respect to an axisparallel to the axis of rotation of the wheel. The terms “bike,”“cycle,” “unicycle,” and “vehicle” may all be used interchangeablyherein to indicate a one-wheeled vehicle constructed according to thepresent disclosure. Electric-powered unicycle devices and systems aredescribed in U.S. Patent Publication No. 2012/0217072, which is herebyincorporated by reference in its entirety for all purposes.

Unless otherwise specified, a powered unicycle according to the presentdisclosure, and/or its various components, may but are not required tocontain at least one of the structure, components, functionality, and/orvariations described, illustrated, and/or incorporated herein.Furthermore, the structures, components, functionalities, and/orvariations described, illustrated, and/or incorporated herein inconnection with the unicycle may, but are not required to, be includedin other similar apparatuses.

FIG. 1 shows a schematic diagram of certain main components of a poweredunicycle 10 constructed according to the present disclosure. Unicycle 10may include any suitable single-wheeled vehicle configured with a drivesystem contained in the wheel and a multi-input, auto-balancing controlsystem controlling the drive system. In the example depicted, unicycle10 may include a wheel assembly 12 driven by one or more motors 14,which in turn are controlled by a controller 16 receiving one or moreinputs 18.

Wheel assembly 12 may include any suitable single-wheeled structureconfigured to contain a drive system substantially within a wheel.Examples of such wheel assemblies are described in further detail below.Motor or motors 14 may include any suitable motor and/or other primarymover configured to rotate the wheel of wheel assembly 12. For example,motor 14 may include a battery-powered electric motor operativelyconnected to wheel assembly 12 such that rotation of the motor causesrotation of the wheel. Gearing and timing systems and the like may beincluded in a drive system to facilitate driving of the wheel by motor14. These systems are also described in further detail below.

Controller 16 may include any suitable electronic controller configuredto automatically adjust the speed and/or direction of the wheel based onthe states of certain inputs 18. In the example shown in FIG. 1, theseinputs 18 may include an attitude input 20, a tilt adjust input 22,and/or a braking input 24. In some examples, controller 16 may includeone or more suitable interconnected electronic circuits, memory storageunits, motor controllers, and/or control chips configured to carry outsoftware and/or firmware instructions to control motor 14.

Attitude input 20 may include any suitable input configured tocorrespond to a physical orientation of vehicle 10. Input 20 may beprovided by an attitude sensing system 26. Attitude sensing system 26may include any suitable sensors and/or apparatuses configured todetermine an orientation of vehicle 10 in space relative to the centerof the earth. For example, attitude sensing system 26 may include one ormore sensors 28 for determining pitch, roll, and/or yaw. In theseexamples, the terms pitch, roll, and yaw are used with their standardmeanings. Accordingly, pitch may be defined as pivoting about an axisparallel to an axis of rotation of the wheel, interchangeably termed the“Y” axis. Pitch may also be described as tilting a nose of the vehicleup and down. Roll may be defined as pivoting about an axis parallel tothe direction of travel of the vehicle, interchangeably termed the “X”axis. Roll may also be described as tilting the vehicle side to side.Yaw may be defined as pivoting about an axis parallel to a vertical axisthrough a center of the wheel, interchangeably termed the “Z” axis. Yawmay also be described as rotating the wheel left and right, such as whenchanging a heading or direction of travel.

In some examples, sensors 28 may include one or more inclinometers,accelerometers, and/or gyroscopes. For example, a roll-type sensor 28may include an accelerometer in combination with a gyroscope to form aninclinometer configured to sense a roll orientation. Sensors 28 may beaffixed to vehicle 10. In some examples, sensors 28 may be collocatedwith controller 16, such as on a common circuit board or within a commonenclosure. In some examples, sensors 28 may be located near a center ofgravity of the vehicle, such as within wheel assembly 12. This locationmay improve accuracy of the sensors with respect to the actualorientation of the vehicle, as opposed to a location farther from thecenter of gravity.

Controller 16 may be configured to respond to attitude input 20 byautomatically adjusting motor 14 to reduce the difference between themeasured orientation and a desired orientation. For example, a measuredor sensed pitch may be compared to a desired pitch orientation. If theactual pitch is different from the desired pitch, the controller mayincrease or decrease the speed of motor 14 to reduce the difference. Thedesired pitch may be referred to as the “zero pitch setpoint” or “zerosetpoint.”

In some examples, the zero pitch setpoint may be substantiallyequivalent to a pitch of zero degrees from vertical, which maycorrespond to a vertical and/or balanced unicycle. In these examples, ifthe bike tips forward, sensors 28 will detect a pitch indicating thatthe nose of the bike is tipped downward from horizontal, and pass thatpitch to the controller. The controller will compare the sensed pitch tothe zero setpoint, and will determine that a difference exists in theforward direction. In some examples, this difference may be positive,while a difference in the tipped-backward direction may be negative.

The controller will then take action to reduce the positive differentialor delta between the sensed and desired pitch. In this example, thecontroller may increase the speed of motor 14 to drive the wheel forwardand reduce the forward pitch of the bike. As this action takes effectand the sensed difference approaches zero, the controller may causeacceleration of the motor to level off, and a new equilibrium may bereached at a new higher speed. Similarly, determining that a negativedelta exists may cause a reduction in motor speed or may cause a changein motor direction. Accordingly, a user (interchangeably termed a“rider” or an “operator”) may control the speed of unicycle 10 byleaning forward or backward to shift a weight distribution and therebytilt the vehicle, causing the sensed pitch to vary from the zerosetpoint and the controller to compensate as discussed above.

In addition to a pitch-type sensor providing an input to allow thecontroller to compensate for variations from a desired pitch, othersensor inputs may be received by the controller to carry out variousother functions. For example, a roll sensor input may be compared to anexpected range of roll orientations to determine whether the vehicle hasfallen over. In this example, the controller may be configured to shutoff power to the vehicle, or to selected subsystems such as the drivesystem, when such a condition is sensed.

In some examples, the pitch sensor may provide skewed information whencertain conditions exist, such as when turning the vehicle creates asignificant centrifugal force. In this condition, the skewed pitchsensor may send erroneous information to the controller, leading thecontroller to incorrectly conclude that a pitch correction is needed.The inventors have determined that the controller may compensate forthis previously unexpected skewing condition using an input from theroll sensor. When unicycle 10 turns, the wheel necessarily tilts on theX axis, resulting in a roll value that indicates a turn may be inprogress. This information may be used to compensate for the resultingskewed pitch input, for example by offsetting the sensed pitch value bya predetermined or calculated amount.

Controller 16 may receive tilt adjust input 22 from a first user inputdevice such as a tilt adjust control 30. Tilt adjust control 30 mayinclude any suitable mechanical or virtual user interface deviceconfigured to allow a user to communicate a desired tilt adjust amountto controller 16. For example, tilt adjust control 30 may include adial, switch, pushbutton(s), lever, and/or keypad. Any of these userinput devices may be implemented mechanically or virtually, such as inthe case of a graphical user interface (GUI) on a screen or otherdisplay mounted on or otherwise associated with unicycle 10. In someexamples, a user input device may include a voice user interface capableof speech recognition, through which a user may provide voice commandsto the controller.

Regardless of the type of user input device, input 30 may be used tooffset the zero pitch setpoint by an amount corresponding to the input.For example, a user may push a first button to communicate to thecontroller that the zero setpoint should be offset by one degree in apositive direction. In this example, the user may press a second buttonto communicate an offset of one degree in a negative direction. In otherexamples, a user may communicate the desired offset by turning acontinuous or discrete dial, entering a number on a keypad, etc. Inresponse, controller 16 may offset the zero setpoint by the desiredamount, or by a corresponding amount.

For example, if a “three degrees forward” offset is indicated by theuser, the zero setpoint may be adjusted to three degrees forward ofvertical, and the controller would then use that new zero setpoint forcomparing to actual pitch when controlling motors 14. In this example,the controller would attempt to maintain the unicycle at a three degreeangle rather than the original zero degrees from vertical. Using thetilt adjust control in this manner, a user may adjust the desired tiltangle of the bike, in real time. This may be desired, for example, tocompensate for a rider's body type, weight distribution on the bike,user comfort, and/or support surface inclines and declines.

The offset amount may be implemented in software or firmware by using astatic variable, such that the desired offset amount remains at thevalue communicated by the user until the user provides a differentinput, such as via tilt adjust control 30. Furthermore, the value ofthis offset amount may be stored in nonvolatile memory such that thezero setpoint is offset by the same amount even if power to thecontroller is cycled. In some examples, a similar result may be achievedby using a hardware implementation, such as by providing a tilt adjustcontrol 30 in the form of a dial that remains in a set position untilthe user sets a different position. In some examples, stored userprofiles may be provided, and each user profile may have its own customoffset value. In these examples, a user may select one of theestablished profiles and the zero setpoint may be adjusted accordingly.

Controller 16 may receive braking input 24 from a second user inputdevice such as a braking control 32. Braking control 32 may include anysuitable mechanical or virtual user interface device configured to allowa user to communicate a desired braking amount to controller 16. Forexample, braking control 32 may include a hand-operated lever typical inbike and motorcycle braking systems, but may also or instead include oneor more controls such as a dial, switch, pushbutton, and/or keypad. Aswith control 30, any of these user input devices (and any other userinput devices or controls associated with unicycle 100) may beimplemented mechanically or virtually, such as via a graphical userinterface (GUI) on a screen or other display. Also as with control 30,control 32 may include a voice user interface capable of speechrecognition, through which a user may provide voice commands to thecontroller.

Regardless of the form of control 32, braking input 24 may becommunicated to controller 16, which may in turn use the input in asoftware- or firmware-controlled braking system. The braking system maybe a regenerative braking system in which motors 14 are turned intoelectrical generators, dumping energy into the associated battery orbatteries. The inventors have found that a regenerative braking systemis generally sufficient for braking of a unicycle 10. Friction brakesmay be included for additional braking capabilities, in someembodiments.

Controller 16 may control motors 14 in the software-controlled brakingsystem in a fashion similar to the tilt adjust control system discussedabove. In some examples, in response to braking input 24, the zerosetpoint may be offset to artificially indicate to the controller thatthe unicycle is tipping over backward by some amount. To compensate, thecontroller will slow the motors, causing them to enter aregenerative-braking state if necessary to further slow the vehicle.This system may be in addition to the option a rider has to lean back toslow the vehicle.

FIGS. 2 and 3 depict an illustrative powered unicycle generallyindicated at 100. Unicycle 100 may be an example of unicycle 10, and mayinclude a wheel assembly 102 containing a drive system, a fork assembly104 attached to the wheel assembly, and a frame portion 106.

Wheel assembly 102 may include a wheel 108 configured to rotate on anaxis of rotation 110 and having a rim 112 on which may be mounted a tire114. Wheel 108 may include any suitable wheel, and may be a typicalmotorcycle racing wheel. In some examples, wheel 108 may be hubless. Inother examples, wheel 108 may have a hub and may be configured as shownin FIGS. 4 and 5, with rim 112 having an internal circumference orperimeter P and a width W defined between two opposing flanges 116 and118. As shown in FIGS. 4 and 5, a mounting surface 120 of wheel 108 maybe offset to one side to form an internal space 122 in wheel 108 definedby the rim and the mounting surface. Mounting surface 120 may be anysuitable rigid surface for attaching wheel 108 to a drive system. Forexample, mounting surface 120 may include a metal plate having multiplethrough-holes arranged in a pattern to accommodate mounting bolts andlug nuts. Mounting surface 120 may be connected to rim 112 by asubstantially solid plate 124 or by other suitable structures such asspokes. In some examples, plate 124 may include apertures 126 or slotsfor weight reduction, which may be arranged symmetrically aroundmounting surface 120 as shown in FIGS. 4 and 5.

Tire 114 may be attached to rim 112, such as at flanges 116 and 118, andmay include any suitable tire configured to provide an interface betweenthe rim and a support surface. In some examples, tire 114 may include astandard 200 mm motorcycle racing tire, which may be mounted to a17-inch diameter×6-inch wide automotive example of a rim 112. In someexamples, tire 114 may include a rounded or peaked profile to facilitateleaning and maneuverability while balancing the vehicle.

Returning to FIGS. 2 and 3, frame portion 106 may be mounted above wheelassembly 102. Frame portion 106 may include any suitable structureconfigured to provide a skeletal support for operatively connectingvarious components to the wheel assembly. For example, frame portion 106may include a tubular framework configured to support a rider interfaceincluding a handlebar 128 and a seat assembly 130. Frame portion 106 maybe constructed of any suitable materials, and may include aluminumtubing such as the tubing used in bicycle frame construction. Thistubing may be formed into aesthetically pleasing appearance, which maybe further enhanced by decorative body panels 132 attached to the frame.Body panels 132 may include any suitable lightweight plates or panelsconfigured to attach to frame portion 106. Body panels 132 may, forexample, provide decoration and/or color, cover gaps or frame tubes,and/or display information such as a company logo. In some examples,body panels 132 may include cowlings or fairings. In some examples, bodypanels 132 may include vacuum-formed rigid plastic plates. Frame portion106 may include various attachment points, tabs, apertures, bosses, andthe like for attaching these and other accessories such as saddle bags.

Handlebar 128 may include any suitable structure configured to providesupport for the weight of a rider as well as a steering interfacebetween the rider and the bike. In some examples, handlebar 128 may alsoprovide a mounting surface for attaching accessories and/or controls. Inthe example depicted in FIGS. 2 and 3, a generally straight handlebar128 having hand grips at opposite ends is attached at a forward endportion of frame portion 106. While a generally straight handlebar isdepicted in this example, other standard and non-standard handlebarconfigurations may be suitable.

A brake lever 134, which is an example of brake control 32, and atwo-button attitude adjust control 136, which is an example of control30, may be mounted to handlebar 128 in locations easily accessible bythe hands of the rider. A display module 138 may also be mounted to thehandlebar, and may display information such as battery charge, powerusage, tilt angle, and/or other information useful to a rider oroperator. These controls and interfaces may be in electroniccommunication with the controller via cables (not shown) and/or by aBluetooth and/or other wireless connection.

In some examples, frame portion 106 may include an extension member orcrash bar 140 extending generally in the direction of travel of thevehicle. Crash bar 140 may include any suitable structure configured tocontact a support surface 142 (such as the ground or a road) whenunicycle 100 is pivoted forward about the Y axis, and to support theweight of the unicycle. In some examples, a structure such as akickstand may be used to prevent the vehicle from tipping over in thispivoted mode. In some examples, crash bar 140 may itself be furtherconfigured to bias the vehicle against tipping over sideways when thevehicle is resting on the crash bar. In the example depicted in FIGS. 2and 3, crash bar 140 is configured as a hoop structure having twomembers extending forward and a crossbar connecting the distal ends ofthe members. Resilient bumpers 144 may be affixed to contact points oncrash bar 140.

Because crash bar 140 may support the weight of the vehicle and mayfurther prevent tipping, unicycle 100 may be placeable into two modes. Afirst, or operational mode may include riding the vehicle in a generallyvertical orientation with the single wheel contacting support surface142. A second, or parked mode may include placing the vehicle in atilted-forward position with the crash bar contacting support surface142. The second mode may require the controller and/or motors to be atleast partially disabled or inactivated such that the forward tippedposture of the vehicle is not automatically sensed and compensated for.

Seat assembly 130 may be operatively connected to and supported by frameportion 106. With continuing reference to FIGS. 2 and 3, as well as withmore specific reference to FIG. 6, seat assembly 130 may include a seatportion 146 adjustably mounted to a support frame 148 by an adjustmentassembly 150 including a spring in the form of a shock absorber 152.Seat portion 146 may include any suitable structure configured tosupport a human rider in a seated position, and may further beconfigured to allow a rider to straddle the seat in a crouched orstanding position. For example, seat portion 146 may include a standardmotorcycle or bicycle seat.

The seat may be adjustable in one or more directions, as shown in FIG.6. In the example shown, the seat is supported by adjustment assembly150 at a front end on a slotted hinge connection and at a rear end on aslotted bracket connected to shock absorber 152. The upper end of shockabsorber 152 may be selectably positioned in the slot and clamped inplace, such as by a quick-disconnect lever-operated clamp similar tothose typically used to attach bicycle wheels to bicycle fork dropouts.Because the rear slotted bracket is angled, and the lower end of shockabsorber 152 is pivotable at a fixed location on the frame, changing theposition of the shock in the slot will change both the height and theangle of seat portion 146. In some examples, seat portion 146 may beadjustable from approximately 30 inches to approximately 38 inches abovethe ground. In other examples, seat assembly 130 may be mounted to frameportion 106 in a fixed position. In some examples, seat assembly 130 mayinclude a circumferential frame and/or a fixed rear handle, such as ahoop handle 153 shown in the drawings.

Turning now to FIGS. 7 and 8, and with continued reference to FIGS. 2and 3, frame portion 106 may include a pivotable connection 154 to forkassembly 104. Pivotable connection 154 may include any suitablestructure configured to allow frame portion 106 to pivot generally sideto side relative to fork assembly 104. For example, pivotable connection154 may include a head tube 156 oriented at a head tube angle 158,further described below. Pivoting of the frame may be limited by amechanical stop 160. Mechanical stop 160 may include any suitablestructure configured to limit pivoting of the frame to a predeterminedrange. In the example shown in the drawings, mechanical stop 160includes a member 162 having one end affixed to a rotating portion ofhead tube 156 and an opposite end protruding through an aperture in afork crown bracket 164 fixed to fork assembly 104.

Pivoting of frame portion 106 relative to fork assembly 104 may beadditionally or alternatively limited by a four-bar linkage mechanism. Aschematic four-bar linkage mechanism 166 is depicted in FIG. 9.Mechanism 166 may include four links 168, 170, 172, and 174, attached toeach other at four pivoting connections, A, B, C, and D. In thisexample, opposing pairs of links are substantially equivalent in lengthand parallel to each other. As shown in FIG.

9, if link 168 is held fixed, the other three links may be pivoted fromside to side, and opposing links remain substantially parallel to eachother at all times. Accordingly, mechanism 166 may be referred to as aparallelogram four-bar linkage mechanism. Importantly in this example,link 172 opposite to link 168 remains in the same orientation throughoutpivoting of the linkage.

Returning to FIG. 8, the conceptual four-bar linkage mechanism 166 maybe implemented in the depicted example of frame portion 106. In thisexample, frame portion 106 includes a drag link 176 attached at a frontend to a bell crank bracket 178 and at a rear end to fork crown bracket164. Drag link 176 is parallel to and offset to one side from thecenterline of frame portion 106. Accordingly, in this embodiment, forkcrown bracket 164 corresponds to link 168, drag link 176 corresponds tolink 170, bell crank bracket 178 corresponds to link 172, and frameportion 106 corresponds to link 174.

Bell crank bracket 178 may include any suitable linking structureconfigured with two rotatable connections offset from each other. In theexample shown, bell crank bracket 178 is a teardrop-shaped plate withthe drag link attached to the smaller end of the teardrop and thehandlebars attached at the larger end of the teardrop. Bell crankbracket 178 may be interchangeably termed the “front bell crank” andfork crown bracket 164 may be interchangeably termed the “rear bellcrank” due to their similar functions in this context. The handlebarattachment is formed as a pivoting connection by including a rotatablehead tube 180 configured such that handlebar 128 is independentlypivotable relative to frame portion 106, but is pivotably coupled tobell crank bracket 178 such that they turn together.

As in mechanism 166, this forms a parallelogram four-bar linkagemechanism with a fixed link at bracket 164 and four rotatableconnections. To facilitate return of the mechanism to a neutral, centerposition, a return spring or other biasing mechanism may be included.For example, a return spring 181 may function to return the frameportion to a center position. In some examples, return spring 181 mayinclude two springs mounted inline or coaxially with respect to the draglink on either side of a spool-type bracket.

Swinging the free end of frame portion 106 side to side about head tube156 at the pivoting end of frame portion 106 causes handlebar 128 toswing with the frame. However, the four-bar linkage causes handlebar 128to remain generally parallel to the Y axis at all times. Among otherthings, this facilitates an intuitive steering experience for the rider.

As best seen in FIGS. 2 and 3, fork assembly 104 connects frame portion106 to wheel assembly 102, and may include two main legs 182 configuredto straddle the wheel assembly, with proximal ends 184 of the two legsmeeting at or connected to fork crown bracket 164. Unlike with typicalforks, distal ends 186 here may be attached to points on the wheelassembly spaced from axis of rotation 110. For example, wheel assembly102 may include left and right hub cover plates 188 and 190, and distalends 186 of legs 182 may each be attached to a respective hub coverplate at a point above the axis of rotation, as shown in the drawings.

Fork assembly 104 may further include additional bracing and/orframework such as rear trellis 185. Rear trellis 185 may include anysuitable structure configured to reinforce the connection between legs182 and fork crown bracket 164, and may further facilitate connection offork assembly 104 to other components of unicycle 100. For example, reartrellis 185 may include tubular frame components, connection points,buttress plates, and/or braces. In some examples, rear trellis 185 mayprovide a support and connection framework for attaching a fender 187 asshown in FIGS. 2 and 3.

Hub cover plates 188 and 190 may each include any suitable rigidstructure configured to substantially cover the lateral portions ofwheel 108 within the diameter of the rim, and to provide supportiveconnection points for both fork 104 and a drive system disposed withinspace 122. One or both of the hub cover plates may include a bracket,brace, and/or other reinforced portions configured to facilitate a rigidsupport structure. Hub cover plates 188 and 190 may each includeapertures or access ports, such as for accessing one or more batterieswithin space 122 without removing the hub cover plate. Theunconventional attachment of fork assembly 104 may facilitate suchaccessibility through the side of the wheel, because the fork legs donot physically interfere with access. The interaction of fork assembly104 with other components of unicycle 100 is further discussed belowregarding FIG. 13.

Steering of unicycle 100 may be affected by various aspects of thestructures and mechanisms described above to create a more intuitivedriving experience for the rider. In general, steering may beaccomplished by leaning and redistributing weight on the vehicle inorder to cause the wheel to go where the rider desires. The pivotableframe portion and four-bar linkage mechanism may facilitate steering byallowing the rider to further redistribute his or her weight by throwingthe front end of the frame, and the seat on which the rider is seated,over to one side of the vehicle. Maintaining handlebar 128 square withrespect to the wheel during this activity may further aid insteerability. Additionally, when the frame reaches the mechanical stop,added torque is placed on the fork assembly and therefore on the wheelassembly.

Further assisting in an intuitive steering experience is the geometry ofthe frame-to-fork connection. As described above, the pivot pointconnection at head tube 156 may be angled and located behind themidpoint of the vehicle. Head tube angle 158 may be in the range ofabout 15 degrees to about 35 degrees, and the inventors have found anangle of about 20 degrees to be suitable. Head tube 156 may be offsetsuch that an imaginary line 192 drawn through the central long axis ofthe head tube intersects with support surface 142 behind the point wherewheel 108 contacts support surface 142. A distance between the intersectpoint and the wheel contact point may be about four to about ten inches,and in some examples may be about five inches, although other offsetsmay be suitable.

Turning now to FIGS. 10 and 11, an illustrative drive system 200suitable for use with unicycle 100 is depicted in two differentisometric views. Also, in FIG. 12, system 200 is depicted with onlycertain drive components shown in an isometric view to illustrate therelationships between those components. Drive system 200 may include anysuitable devices and components configured to fit substantially withininternal space 122 of wheel 108 or a similar wheel and to providesustained rotational force to rotate the wheel in either direction,thereby causing the vehicle to travel across support surface 142. Inthis example, drive system 200 includes a housing 202, two electricmotors 204 and 206, a main drive pulley 208, a countershaft 210, acountershaft pulley 212, a main lug pulley 214, and an axle 216.

Housing 202 may include any suitable structure configured to house acontroller and a battery or batteries, and to provide structural supportand connection points for mounting the various drive components. In thisexample, housing 202 is a rigid metal housing having an uppercompartment 218 for containing an electronic controller (not visible)substantially similar to controller 16, a battery compartment 220 forhousing one or more batteries 222, and a lower drive mounting portion224 for mounting the various moving parts of the drive system. Axle 216passes through the central portion of the housing, and in this exampleis a non-rotating shaft on which other components may be supportedand/or mounted.

Electric motors 204 and 206 may be mounted to housing 202 on oppositesides, and transverse to the direction of travel of the unicycle. Themotors may include any electric motors suitable for driving wheel 108with sufficient power to facilitate transportation of an adult humanacross support surface 142 at a reasonable speed. In some examples, asingle motor may be used. In some examples, non-electric motors may beincluded, such as two- or four-stroke internal combustion engines. Inthe example depicted in the drawings, each motor is a 1,000 Wattelectric motor.

Motors 204 and 206 may be powered by storage battery or batteries 222.Batteries 222 may include any portable power storage device capable ofproviding adequate power to motors 204 and 206 for a desired usageperiod. In some examples, batteries 222 may include Lithium-Ionbatteries and/or lead acid batteries. Batteries 222 may be rated at 30amp-hours of battery life with 150 amps of peak current flow to themotors. As discussed above, batteries 222 may be housed in batterycompartment 220 of the housing, and may be accessible through an accessport or window on a side of wheel assembly 102 without disassembling thevehicle.

Motors 204 and 206 may be operatively connected to a common drive pulleyin the form of main drive pulley 208 by respective timing belts 226 and228 as shown in FIGS. 11 and 12. The resulting torque created by maindrive pulley 208 is transmitted to countershaft pulley 212 on theopposite side of housing 202 by countershaft 210. The term “jackshaft”may be used interchangeably with the term “countershaft.” A main drivebelt 230 then transfers the torque from the jackshaft pulley to main lugpulley 214, which rotates around stationary axle 216. In some examples,chains or other transmission devices may be used in place of one or moreof the belts just described. In some examples, one or more additionaltypical supporting components may be included, such as idler pulleys,belt tensioners, torque rods, etc., all carrying out their standard andknown functions.

Main lug pulley 214 may include a plurality of lugs 232 for mountingwheel 108, such as by attaching mounting surface 120 of the wheel to thethreaded lugs using lug nuts (not shown). This mounting method may besubstantially similar to the standard method of attaching an automotivewheel to a car when changing a flat tire. Accordingly, the wheel may beaffixed to the main lug pulley, and the torque of main lug pulley 214may be transferred to wheel 108. Motors 204 and 206 thereby indirectlycause the wheel to rotate. The controller and associated systems cantherefore control the speed and direction of wheel 108 by controllingthe speed and direction of the motors. One or more speed sensors may beincluded in drive system 200 for providing the controller with feedbackregarding actual speed of the motors and/or wheel.

Turning now to FIG. 13, a rear plan view of a portion of unicycle 100 isdepicted, showing the connections between fork assembly 104, hub coverplates 188 and 190, housing 202, and axle 216. In general, thesestructures are affixed to each other as shown and as explained below,and wheel 108 is mounted only to the lug pulley as described above,allowing the wheel to spin freely around the housing and within the forkand hub cover plates, none of which is attached directly to the wheel.As depicted in FIG. 13, legs 182 of fork assembly 104 straddle the hubcover plates, mounting directly to the plates above the axle. Housing202 is bolted directly to left hub cover plate 188, and may further beattached to axle 216. Right cover plate 190 is attached to axle 216.Accordingly, the combination of the fork, hub plate, housing, and axlemay form a rigid unitary structure capable of supporting the wheel andtransferring torque and other moments from the rider and steering systemto the wheel.

Foot pegs 234 and 236 may be attached to respective hub plates, ordirectly to opposite ends of axle 216. Foot pegs 234 and 236 may includeany suitable structure configured to support a rider's foot, in aresting and/or standing posture, and to transfer torque from the feet ofthe rider to the wheel assembly. In some examples foot pegs 234 and 236may be hinged to allow them to be folded out of the way as desired. Insome examples, crash bars 238 may be provided near foot pegs 234 and236, respectively, as shown in FIGS. 2 and 3. These crash bars mayextend laterally beyond the hinged connection of foot pegs 234 and 236,and may provide protection from the foot pegs, such as to a rider's legwhen passing by or to an underlying surface when storing or otherwiselaying the vehicle on its side.

In addition to the other aspects of vehicle steering described above,foot pegs 234 and 236 may also enhance or facilitate steering ofunicycle 100. The foot pegs may be used by a rider as a steering controlinput. Because the steering pivot at head tube 156 is behind the axis ofrotation of the wheel, the rider may be able impart a twist directly onthe wheel as if standing on a plank balanced on a fulcrum. This twistmay cause the wheel to lean over and follow a turning arc. Thisrider/foot peg interaction, in conjunction with leaning of the rider'sbody and moving of the handlebars side to side, may allow the rider manydegrees of freedom in steering. This, in turn, may facilitate tasks suchas traversing uneven terrain.

Other examples of a drive system suitable for use in a unicycleconstructed according to the present disclosure is depicted in FIGS.14-16 and generally indicated at 300. Drive system 300 is a hublessdrive system, also referred to as a rim drive system. In this example,the wheel of the unicycle is a hubless wheel 302, which may include arim 304 and an attached tire 306, but which does not include structuressuch as mounting surface 120 or spokes 124. Drive system 300 may includea housing 308 disposed within internal space 310 of rim 304, one or morebattery-powered motors 312 operatively connected to one or morerespective drive pulleys 314 by belts 316, one or more drive sprockets318 associated with each drive pulley 314, and a ring gear 320 disposedon an inner surface of rim 304. Idler rollers 322 may be attached tohousing 308 at various points around the circumference of the rim tomaintain the housing positioned properly within the rim. In otherexamples, the idler rollers may themselves be driven by one or moremotors, providing a frictional drive by interacting directly with rim304. In some examples, drive system 300 and/or housing 308 may not takeup the entirety of space 310, leaving an opening or void orthrough-space in the wheel and revealing the hubless nature of theassembly. An example of this type of void space is shown above thehousing in FIG. 14.

Drive system 300 may operate to rotate wheel 302 by controlling motors312 to rotate drive sprockets 318 via coaxial pulleys 314. Rotation ofthe rim and wheel may then result from interaction between the rotatingdrive sprockets and the complementary ring gear, which is fixed withrespect to the rim. In some examples, the drive sprockets and the ringgear have complementary teeth. In some examples, the drive sprockets aretoothed, and the ring gear is a drive chain affixed to the rim andhaving spaces corresponding to the teeth of the sprockets.

A fork assembly may attach to housing 308 either directly or via hubplates, similar to the connections described above regarding unicycle100. Because the wheel is hubless and the drive and housing may fit intoa lower portion of the wheel, an open space may be included to revealthe hubless nature of the wheel. In some examples, this space may beused to house one or more batteries. In some examples, the battery orbatteries may be housed in a space between opposing drive motors, suchas in space 324 shown in FIG. 14.

FIG. 17 is an isometric view of an illustrative embodiment in which amounted accessory 340 is operatively connected to the wheel assemblyrather than a seat for a mounted rider as described in the examplesabove. Mounted accessory 340 may be any suitable structure configured tocarry, transport, or otherwise move a load across a support surface on aunicycle according to the present disclosure. In the example depicted inFIG. 17, mounted accessory 340 includes a gurney 342. In this example,gurney 342 may be operatively connected to a wheel assembly 344substantially similar to wheel assembly 102, driven by a drive systemsimilar to drive systems 200 or 300. Because wheel assembly 102 issteerable by leaning, and balancing is automatically controlled withrespect to pitch, a vehicle such as the combination of gurney 342 andwheel assembly 344 may facilitate moving a patient by an operatorholding one end of the gurney. Transport of the vehicle may beaccomplished similar to operating a wheelbarrow, but may besignificantly easier than carrying the gurney or manually pushing orpulling the gurney, especially over rugged terrain or over longdistances.

The vehicle in this example may be capable of carrying a patientweighing up to 350 lbs. The vehicle may be capable of moving at a speedof up to six miles per hour, and may be capable of moving with apassenger on the gurney up an incline of up to about a 30% grade. Insome examples, the vehicle with gurney 342 may include a removablebattery that can be removed without tools and the battery may have arecharge time of six hours.

In some examples, a steering area may be situated at one end of gurney342 , and may include a throttle control, an on/off button, a tiltadjust control, a brake control, and other features desired such as ascreen to display desired information (e.g., hill grade, speed, batterylife, current weight, etc.). The vehicle may be adapted such that thedriver walking behind the vehicle at the steering area can maintain acenter of gravity of the gurney above the wheel. The steeringconfiguration may allow the driver to rotate the substantiallyhorizontally situated gurney in clockwise or counterclockwise directionsin order to effectuate steering while moving. When the vehicle is not inuse, one end of the gurney may rest against the ground in a parkedconfiguration. In some examples, gurney 342 may be equipped with a quickrelease mechanism (not shown), allowing quick removal of the gurney fromthe wheel assembly.

Examples and Additional Details

Any user interface or control associated with a vehicle such as unicycle10 or unicycle 100 may include any suitable physical or virtual userinterface configured to allow an operator to communicate information tothe controller, or to carry out one or more functions of the controlleritself. For example, a user interface may include one or moremanipulable controls such as a lever, dial, switch, slider, pushbutton,keypad, and/or knob, any of which may be implemented mechanically orvirtually, such as via a graphical user interface (GUI) on a screen orother display. Any manipulable control may be manipulated by a body partof the operator, such as by a hand, a foot, and/or one or more fingersor toes. In some examples, a user interface may include a voiceinterface capable of speech recognition, through which the operator mayprovide voice commands to the controller. In some examples, a userinterface may include a wearable computing device, such as an article ofclothing or a wrist- or head-mounted interface. In some examples, a userinterface may include any suitable device implanted on or in theoperator's body.

Unicycles such as unicycle 10 and unicycle 100 may be electric-poweredand therefore lack traditional noises associated with gas-poweredengines. In some embodiments, unicycle 10 may include sound featuressuch that unicycle 10 may project a gas-powered engine noise. Othersound features may include a start-up sound, a revving sound, apower-down sound, and/or any other sound desired. The sound features maybe electronically controlled, such as by modulating control signals toone or more motors. In some examples, this may include pulse widthmodulation. The sound features may be electronically triggered to outputbased on an associated action of unicycle 10 (e.g., turning a key tostart up unicycle 10 may cause a start up sound; movement of unicycle 10may cause a revving or movement sound, etc.). Output of the soundfeature may be generated by the motor itself, or may occur through oneor more speakers coupled to unicycle 10, the one or more speakers beingin communication with the controller of unicycle 10.

Various accessories and auxiliary components may be included in aunicycle according to the present disclosure. For example, a unicyclemay include one or more headlights, taillights, reflective surfaces,hand grips, turn signals, warning lights, and/or audible warning devicessuch as a vehicle horn or bell.

In some examples, a unicycle may include a charging interface to allowthe vehicle to connect to a charging device. The charging interface mayinclude a connector or a non-contact magnetic coil for inductive powertransfer.

Some embodiments of the present disclosure may be described as aone-wheeled vehicle including a centerless wheel.

Some embodiments of the present disclosure may be described as a poweredvehicle having two motors to allow redundancy, different speed settings,and/or variable torque without altering drive gear ratios.

Some embodiments of the present disclosure may be described as includinga rechargeable lithium-ion battery with an about 20 amp-hour or an about30 amp-hour capacity mounted within a battery bay in the wheel. In someembodiments, a prismatic battery form-factor may be used similar tobatteries utilized in some automotive electric vehicles. In otherembodiments, a sealed about 20 amp-hour lead-acid battery may beutilized.

Some embodiments of the present disclosure may be described as aone-wheeled vehicle having one or more electronic controllers housedwithin the wheel above a battery bay. This arrangement may facilitateheat management by placing the electronic components in close proximityto the battery, thus shortening the length of required wiring andreducing associated thermal losses, cable connectors, and cable failure.In some embodiments, a gyro controller board may be placed withinapproximately three inches of two motor controllers for controlling theelectric drive motors, and the motor controllers may be placed withinabout eight inches of the battery and drive motors.

Some embodiments of the present disclosure may be described as aone-wheeled vehicle having software controls. The vehicle may includecomputer hardware and software and the ability to connect to andinteract over a wireless or other network (e.g., wifi, cellular, 3G, 4G,LTE, cable connector, etc.). The vehicle may include one or morecomputing systems that may include standard features such as a screen, amemory, a processor, a wireless antenna, etc. The vehicle may also beconfigured to interact or interface with a computer, such as a laptop, atablet, a PDA, and/or a smartphone.

Some embodiments of the present disclosure may be described as aone-wheeled vehicle having software controls configured to controlvarious functions such as remote starting of the vehicle, lights, radio,security, and/or safety and riding features. The software may be pairedto a smartphone or other computing device over a network so that thesmartphone or other device can interact with the vehicle to access,monitor, and /or control such functions.

Some embodiments of the present disclosure may be described as aone-wheeled vehicle having hardware and software controls configured tocreate a wireless hotspot. The vehicle may be paired to a smartphone orother electronic device such that when the smartphone is within range ofthe hotspot, the vehicle may unlock certain security features. Thevehicle may automatically unlock the security features when thesmartphone is in range or upon receiving an indication from thesmartphone to unlock the features (e.g., the user enters a codeindicating to unlock the cycle). In some embodiments, the vehicle may beon any network and may be paired to a smartphone or other computingdevice over such a network to control, access, or monitor the securityfeatures. The vehicle controller system may have an onboard website thatmay be presented to an external wireless-enabled device through theonboard wireless (e.g., wi-fi) hot spot. Only a standard web browser maybe required.

Some embodiments of the present disclosure may be described as aone-wheeled vehicle having a speed of approximately 12.5 mph; a range ofapproximately 20 miles; two 1,000 W motors for a total of approximately2,000 Watts of power; approximately 30 amp-hours of battery life; andapproximately 150 amps of peak current flow to the motors.

Some embodiments of the present disclosure may be described as aone-wheeled vehicle having an attitude adjustment, or tilt, feature.Attitude adjustment may allow the rider to make minor adjustments in thebalance point of a self-balancing vehicle. This allows the rider to findhis or her particular balance point, so that he or she can easilycontrol the acceleration and deceleration of the vehicle by leaningforward or backward, respectively. A balance point may be affected bythe rider's personal body geometry and weight distribution.Additionally, a balance point may be affected by the terrain, such aswhen riding up or down a hill. In these examples, a tilt adjustment maybe beneficial to maintain rider comfort and balance.

Some embodiments of the present disclosure may be described as aone-wheeled vehicle having an attitude adjustment control with an up anda down button. Pressing the up attitude adjustment button may add asmall negative offset to the balance point of the vehicle, causing thenose of the vehicle to pitch up. Pressing the down attitude adjustmentbutton may add a small positive offset to the balance point of thevehicle, causing the nose of the vehicle to pitch down.

Some embodiments of the present disclosure may be described as aone-wheeled vehicle having an attitude adjustment system wherein anoffset value is stored in nonvolatile memory, so that the offsetpersists between power cycles, allowing a rider to have the vehiclebalanced for riding once the power is turned on and balance is engaged.

Based on the above description and the associated drawings, thefollowing examples in the form of numbered paragraphs describe variousembodiments of apparatuses and methods of the disclosure.

A0. A one-wheeled vehicle comprising:

-   -   a single wheel assembly including a single wheel having an axis        of rotation and a rim having an inner circumference, and a tire        attached to the rim;    -   an electric drive system coupled to the wheel assembly and        substantially contained within the inner circumference of the        rim;    -   a frame including a body having an extension member generally        extending perpendicular to the axis of rotation of the wheel,        and a fork operatively connected to the body, the fork having        two legs straddling the wheel assembly;    -   wherein a distal end of each of the legs of the fork is attached        to the wheel assembly only at a respective connection spaced        from the axis of rotation of the wheel.

A1. The vehicle of paragraph A0, wherein the vehicle is configured totravel in an operational mode in which the vehicle travels with only thesingle wheel assembly contacting a support surface.

A2. The vehicle of paragraph A1, wherein the vehicle is furtherconfigured to convert between the operational mode and a parked mode inwhich the frame is rotated about the axis of the wheel such that theextension member contacts the support surface and resists lateraltoppling of the vehicle.

A3. The vehicle of paragraph A0, wherein the wheel rotates about anaxle, and each of the distal ends of the fork are attached to the wheelassembly above the axle relative to the support surface when the vehicleis in the operational mode.

A4. The vehicle of paragraph A3, the electric drive system furthercomprising a battery, wherein the battery is accessible through the sideof the wheel assembly without interference from the fork.

A5. The vehicle of paragraph A3, the wheel assembly further including afirst hub cover disposed over a first lateral side of the wheel and asecond hub cover disposed over a second lateral side of the wheelopposite the first side, the first hub cover being affixed to the axleand the second hub cover being affixed to the drive system.

A6. The vehicle of paragraph A5, wherein the distal ends of the forklegs are respectively attached to the first and second hub covers.

A7. The vehicle of paragraph A0, wherein the extension member comprisesa hoop structure.

A8. The vehicle of paragraph A7, wherein the hoop structure comprisestwo legs extending generally perpendicular to the axis of rotation and acrossbar oriented parallel to the axis of rotation rigidly linkingdistal ends of the two legs.

B0. A one-wheeled vehicle comprising:

-   -   a wheel assembly including a single wheel having an axis of        rotation and a rim having an inner circumference;    -   an electric drive system coupled to the wheel assembly and        substantially contained within the inner circumference of the        rim;    -   a frame generally oriented perpendicular to the axis of rotation        of the wheel, the frame having a free end portion and a pivoting        end portion;    -   a handlebar operatively connected to the free end portion of the        frame; and    -   a support assembly having a first end pivotably connected to the        pivoting end portion of the frame and a second end affixed to        the wheel assembly;    -   wherein the frame is configured to pivot side to side relative        to the wheel assembly, as limited by a mechanical stop.

B1. The vehicle of paragraph B0, wherein the pivotable connectionbetween the connector assembly and the frame comprises a head tubedisposed behind a vertical line running through the axis of rotation.

B2. The vehicle of paragraph B1, wherein the head tube angle is about 15to about 35 degrees relative to vertical.

B3. The vehicle of paragraph B2, wherein the head tube angle is about 20degrees.

B4. The vehicle of paragraph B1, wherein the vertical line intersects asupport surface at a first point, a line through a long axis of the headtube intersects the support surface at a second point, and the head tubeis offset from the vertical line such that the second point is behindthe first point relative to a forward direction of vehicle travel.

B5. The vehicle of paragraph B0, further comprising a seat assembly forcarrying the weight of a rider, the seat assembly being operativelyconnected to the frame between the free end and the pivoting end.

B6. The vehicle of paragraph B5, the seat assembly further comprising anadjustable spring configured to absorb shocks and to adjust a height ofthe seat assembly relative to the frame.

B7. The vehicle of paragraph B0, further comprising a first bell crankoperatively connected to the free end portion of the frame, a secondbell crank operatively connected to the pivoting end portion of theframe, and a drag link connecting the first bell crank to the secondbell crank, wherein the first bell crank, second bell crank, frame, anddrag link together form a parallelogram four-bar linkage mechanism.

B8. The vehicle of paragraph B7, wherein the second bell crank is fixed,and the handlebar is operatively connected to the first bell crank, suchthat the four-bar linkage mechanism is configured to maintain asubstantially constant orientation of the handlebar relative to thewheel assembly as the frame is pivoted side to side.

B9. The vehicle of paragraph B7, the four bar linkage mechanism furthercomprising a biasing member configured to bias the frame toward aneutral side-to-side orientation.

B10. The vehicle of paragraph B9, wherein the biasing member comprises aspring, the spring being mounted coaxial to the drag link.

C0. A one-wheeled vehicle comprising:

-   -   a wheel assembly including a single wheel having an axis of        rotation and a rim having an inner circumference;    -   a drive system coupled to the wheel assembly and including an        electric motor;    -   a controller for controlling a variable speed and direction of        the electric motor, the controller in electronic communication        with an attitude sensing system;    -   wherein the drive system, controller, and attitude sensing        system are all substantially contained within the inner        circumference of the rim; and    -   further wherein the controller is configured to automatically        adjust the speed and direction of the motor, without a manual        throttle control, to reduce a difference between a pitch        measured by the attitude sensing system and a zero pitch        setpoint.

C1. The vehicle of paragraph C0, further including a first user inputdevice in electronic communication with the controller, the first userinput device being operable by a user to provide a selectable attitudeoffset amount to the controller, wherein the controller is configured toadjust the zero pitch setpoint by the offset amount before comparing theadjusted setpoint to the measured pitch.

C2. The vehicle of paragraph C1, wherein the first user input devicecomprises a two-pushbutton switch mounted to the handlebar, wherein afirst of the two pushbuttons provides a positive amount of attitudeoffset and a second of the two pushbuttons provides a negative amount ofattitude offset.

C3. The vehicle of paragraph C1, wherein the selected attitudeadjustment amount is retained in a nonvolatile memory for maintainingthe adjusted zero pitch setpoint after cycling power to the controller.

C4. The vehicle of paragraph C0, wherein the attitude sensing systemcomprises a pitch sensor configured to determine an up and down rotationof the vehicle about an axis parallel to the axis of rotation of thewheel, and a roll sensor configured to determine a side to side rotationof the vehicle about an axis parallel to a direction of vehicle travel.

C5. The vehicle of paragraph C4, wherein the measured pitch correspondsto a pitch input received from the pitch sensor.

C6. The vehicle of paragraph C5, wherein the controller is configured tocompensate for a pitch error in the received pitch input based on a rollinput received from the roll sensor.

C7. The vehicle of paragraph C4, wherein the controller is configured toshut off power to the vehicle in response to a received roll inputindicating that the vehicle has fallen over.

C8. The vehicle of paragraph C0, further including a second user inputdevice in electronic communication with the controller, the second userinput device being operable by a user to provide a selectably variablebraking input to the controller.

C9. The vehicle of paragraph C8, wherein the controller is configured toslow the vehicle in response to receiving a braking input from thesecond user input device, using only a regenerative braking system.

C10. The vehicle of paragraph C8, wherein the second user input devicecomprises a hand-operated brake lever mounted to the handlebar.

The disclosure set forth above may encompass multiple distinctinventions with independent utility. Although each of these inventionshas been disclosed in its preferred form(s), the specific embodimentsthereof as disclosed and illustrated herein are not to be considered ina limiting sense, because numerous variations are possible. The subjectmatter of the inventions includes all novel and nonobvious combinationsand subcombinations of the various elements, features, functions, and/orproperties disclosed herein. The following claims particularly point outcertain combinations and subcombinations regarded as novel andnonobvious. Inventions embodied in other combinations andsubcombinations of features, functions, elements, and/or properties maybe claimed in applications claiming priority from this or a relatedapplication. Such claims, whether directed to a different invention orto the same invention, and whether broader, narrower, equal, ordifferent in scope to the original claims, also are regarded as includedwithin the subject matter of the inventions of the present disclosure.

What is claimed is:
 1. A one-wheeled vehicle comprising: a single wheelassembly including a single wheel having an axis of rotation and a rimhaving an inner circumference; an electric drive system coupled to thewheel assembly and contained within the inner circumference of the rim;and a frame including a body having an extension member generallyextending perpendicular to the axis of rotation of the wheel, and a forkoperatively connected to the body, the fork having two legs straddlingthe wheel assembly; wherein a distal end of each of the legs of the forkis attached to the wheel assembly only at a respective connection spacedfrom the axis of rotation of the wheel.
 2. The vehicle of claim 1,wherein the vehicle is configured to travel in an operational mode inwhich the vehicle travels with only the single wheel assembly contactinga support surface.
 3. The vehicle of claim 2, wherein the vehicle isfurther configured to convert between the operational mode and a parkedmode in which the frame is rotated about the axis of the wheel such thatthe extension member contacts the support surface and resists lateraltoppling of the vehicle.
 4. The vehicle of claim 2, wherein the wheelrotates about an axle, and each of the distal ends of the fork areattached to the wheel assembly above the axle relative to the supportsurface when the vehicle is in the operational mode.
 5. The vehicle ofclaim 1, the electric drive system further comprising a battery, whereinthe battery is accessible through the side of the wheel assembly withoutinterference from the fork.
 6. The vehicle of claim 1, the wheelassembly further including a first hub cover disposed over a firstlateral side of the wheel and a second hub cover disposed over a secondlateral side of the wheel opposite the first side, the first hub coverbeing affixed to an axle of the wheel and the second hub cover beingaffixed to the drive system.
 7. The vehicle of claim 6, wherein thedistal ends of the fork legs are respectively attached to the first andsecond hub covers.
 8. The vehicle of claim 1, wherein the extensionmember comprises a hoop structure.
 9. The vehicle of claim 8, whereinthe hoop structure comprises two legs extending generally perpendicularto the axis of rotation and a crossbar oriented parallel to the axis ofrotation rigidly linking distal ends of the two legs.
 10. A one-wheeledvehicle comprising: a single wheel assembly including a single wheelhaving an axis of rotation and a rim having an inner circumference; anelectric drive system coupled to the wheel assembly and contained withinthe inner circumference of the rim; a frame including a fork having twolegs straddling the wheel assembly; and an extension member extendingfrom the vehicle in a direction transverse to the axis of rotation ofthe wheel; wherein the extension member includes a hoop structureconfigured to support the vehicle in a parked mode in which the frame isrotated about the axis of the wheel such that the extension membercontacts a support surface and resists lateral toppling of the vehicle.11. The vehicle of claim 10, wherein a proximal end of the extensionmember is affixed to the frame.
 12. The vehicle of claim 10, the framefurther comprising a frame body generally oriented perpendicular to theaxis of rotation of the wheel, a handlebar coupled to a first end of theframe body, and a support assembly coupling a second end of the framebody to the wheel assembly.
 13. The vehicle of claim 12, wherein theframe body is pivotably coupled to the support assembly.
 14. The vehicleof claim 10, further comprising a controller for controlling a variablespeed and direction of the electric motor, the controller in electroniccommunication with an attitude sensing system; wherein the controllerand attitude sensing system are contained within the inner circumferenceof the rim; and further wherein the controller is configured toautomatically adjust the speed and direction of the motor, without amanual throttle control, to reduce a difference between a pitch measuredby the attitude sensing system and a zero pitch setpoint.
 15. Thevehicle of claim 10, wherein only the single wheel of the vehicle andthe extension member are in contact with the support surface when thevehicle is in the parked mode.
 16. A one-wheeled vehicle comprising: asingle wheel assembly including a single wheel having an axis ofrotation and a rim having an inner circumference; an electric drivesystem coupled to the wheel assembly and contained within the innercircumference of the rim; a frame generally oriented perpendicular tothe axis of rotation of the wheel, the frame having a free end portionand a pivoting end portion; a handlebar coupled to the free end portionof the frame; a support assembly having a first end pivotably connectedto the pivoting end portion of the frame and a second end affixed to thewheel assembly; and an extension member extending from the vehicle in adirection transverse to the axis of rotation of the wheel; wherein theframe is configured to pivot side to side relative to the wheelassembly, as limited by a mechanical stop; and wherein the extensionmember is configured to support the vehicle in a parked mode in whichthe frame is rotated about the axis of the wheel such that the extensionmember contacts a support surface and resists lateral toppling of thevehicle.
 17. The vehicle of claim 16, wherein the extension membercomprises a hoop structure.
 18. The vehicle of claim 17, wherein thehoop structure comprises two legs extending generally perpendicular tothe axis of rotation and a crossbar oriented parallel to the axis ofrotation rigidly linking distal ends of the two legs.
 19. The vehicle ofclaim 16, wherein a proximal end of the extension member is affixed tothe frame.
 20. The vehicle of claim 16, wherein the second end of thesupport assembly includes a fork having two legs straddling the wheelassembly, distal ends of the two legs being attached to the wheelassembly at respective positions that are offset from the axis ofrotation of the wheel.